The episode begins with Alexis seating in the living room in the dark reading her iPad as someone starts to sneak up behind her, but she is soon aware of someone behind her and as she turns around Castle jumps out and fires his laser gun thus starting the age old war “Laser Tag.”
Alexis is less than pleased as she is trying to figure out which college she should go to, Oxford or Stanford. Castle would love his daughter to stay close by, but he knows it is her decision so he tries to lighten the mood with a little game of laser tag. Alexis is certainly not in the mood and tells her father that “it is time to holster the guns, and be adults.” Ouch!
Castle is definitely having a hard time having to see his “little” daughter pulling away from him as she is growing up. He talks over his dilemma with Martha, but as he does so Beckett calls, but Castle ignores the call. Martha calls him on the action and he replies that things have been strained between him and Beckett to which Martha sarcastically replies, “I wonder why?!” She tells her son that he is been punishing Beckett through his action and that he should make a final decision on what he should do. Castle agrees and he decides to get ready to meet Beckett on his last and final case with the department.
The case Castle and Beckett investigate is that of the murder of David Lock, a stock broker whose body was found in the parking lot of his brokerage firm. He seems to have died from blunt force trauma to head, but the most interesting element is the bite mark the victim has on his forearm that was caused by the murder. Also, another interesting piece of evidence is that a 140 year old piece of cloth was found of the body. Beckett and Castle speak to David’s boss who says that David was involved in a recent altercation when someone keyed his car. David believed it was fellow employee, Charlie Locke a man who was vying for a recent promotion alongside David, who ultimately received the promotion instead of Charlie. This being said, David’s boss notices, Charlie’s car parked next to David’s which is odd since Charlie never showed up to work.
Castle and Beckett go to Charlie’s apartment where they find him handcuffed to a radiator yelling “it isn’t say to be around me” over and over to Beckett and Castle. Charlie even goes so far as asking Beckett to shoot him before he “turns.” Beckett and Castle ask him to elaborate on what he means by “turning” and he says the same thing that bit and killed David, bit him and he is afraid of turning into that monster. Beckett tries to get him to describe what the monster is and Charlie keeps on denying for fear of being ridiculed. Finally, Beckett gets him to talk and he says the monster is a….zombie!
Beckett of course doesn’t believe him, but Castle does stating to Ryan “the higher the intellectual, the tastier the brain,” would explain David’s death. But when Ryan plays security footage of ghastly zombie (think cross between Thriller backup dancer meets Interview with the Vampire) staggering outside the parking lot minutes before David’s murder, there may be a zombie on the loose.
Following the next day, Castle is at home about to review the security video footage along with Martha when Alexis descends from the ceiling surprising her father in her laser tag gear and scoring a point in this round. She explains that yesterday was all a ruse to lure her father in a false sense of security. Back at the prescient evidence is found leading Charlie Locke to be no longer considered a suspect, but he refuses to leave the holding cell for fear he may turn into a zombie and go on a killing rampage. With nothing they can do, the team leaves Charlie in there.
Castle, Beckett and Ryan all debate the idea of “zombies” and whether or not it is a possibility that their killer could be one, when Esposito comes in with evidence that their victim spent two hours before arriving to work on a booty call for a woman named Greta. Ryan and Esposito following this new lead the duo talks to Greta and comes to learn that Greta broke off the fling with David once her fiancé found out about her affair. Ryan and Esposito then question about her fiancé’s whereabouts the night of the murder and its revealed that Tom (her fiancé) was missing around the time David was murder.
Tom is brought in from questioning and he confirms finding about his fiancé’s affair and being upset about it, but he denies any involvement with the murder claiming to be at the Hudson Law Library studying for an exam. When his alibi checks out our favorite crime fighting team is back to square one with no viable suspects. Ryan however informs Beckett and Castle that a chemical found on David’s body match a chemical found in a specific location of a warehouse district. Castle and Beckett head on over to the district, where they encounter two people running past them from an alley telling Castle and Beckett to run for their lives, not knowing what they are running from, the duo decides to investigate and they find zombies, lots of zombies.
Hordes of zombies begin to swarm around Beckett and Castle coming from all sides, but when Beckett yells out NYPD the man-eating zombies stop there “attack” to explain that they are part of zombie tag. It is basically when people dress up some as zombies and others as “normals” then it just like a game of tag except, if the zombie catches a “normal” then that person is turned into a zombie. Beckett and Castle bring in all the zombies interviewing and looking for their own mysterious zombie till they come across the ring-leaders of the group. One of the ring-leaders, Paul who happens to be high, identifies the zombie from a still from the security footage as Kyle Jennings. Ryan and Esposito go to Kyle’s apartment where they find Kyle still in his zombie makeup and costume dead on his living room floor. Kyle’s body is shipped over to the morgue where Castle and Beckett arrived just in time for the autopsy, but before the Medical Examiner could begin, Kyle comes back to life staggering out of the room with Beckett on the chase.
Sometime later, Kyle is found and brought to the hospital and is coherent enough to start talking. He tells Beckett that yes he is part of the zombie tag, but doesn’t remember anything from a day or so ago, even his doctor confirms that Kyle was drug to such a complacent point, that anyone could make him do anything just by telling him so. Beckett and Castle re-interview Paul, from the zombie group to ask about if he was under the influence of the same drug that Kyle was dosed with. He confirms it was the same type of drug and when he starts to describe the drug dealer, the description turns out to be an exact match for Tom, Greta’s fiancé or the girl that David was having an affair with.
Beckett and Castle bring back Tom laying all the facts on the table that Tom is a part time drug dealer that is how he is able to afford law school and his fancy apartment. It is also how Tom came in possession of the drug that he ultimately used to dose Kyle to help him get Kyle to kill David after David vowed to win Greta back. Tom knows there is no way that the pair has evidence and is cocky as ever to say this to their faces, still Beckett locks up Tom for the mandatory forty-eight hours so she can gather evidence to look Tom away . However, things are not looking so good when none of the evidence is linking back to Tom. As a last resort Castle and Beckett try to get through to Greta so she can turn on Tom, but she doesn’t fall for that tactic and the team has to let Tom go, but before they can do they happen to let information slide that Kyle has been released on bail. Tom starts to get nervous because he thinks the cops informed Kyle that he is a possible suspect to his drugging and was the one to make him kill David.
Tom demands for police protection which Beckett agrees to. Esposito is the one to drive him back to his place, but in the parking lot Kyle dressed up in his zombie costume starts to attack the car. Kyle is able to knockout Esposito and is about to hit Tom with a baseball bat, but before he does Tom confess to drugging him and making him kill David and that is when Esposito miraculously gets up and tells Kyle “that is enough.” Beckett also comes out of hiding and that is when Tom realizes that it a setup and that it is not really Kyle in the zombie makeup, but Castle.
Beckett and Castle book Kyle on murder charges and Kyle thanks Castle by giving his zombie costume to him. Beckett tells Castle a bit about her therapy sessions and says that she is almost ready to deal with everything that has happened and that her walls are about to come down and she would like Castle to be there right beside her. Castle states that there is no other place he would be. He then proceeds to go back home and scare Alexis to death with his new zombie look, but as well as winning the laser tag game the two had. Alexis informs her dad that she is planning to go to Stanford, because she would miss her dad to much (much to Castle’s delight) but begs him to let her grow as an adult and not stop at her dorm room every weekend. He agrees and the two start another of laser tag, with Castle vowing to win a second time, but well more enjoying the fact that he hasn’t lost his little girl after all.
Promo for next week’s finale episode!